2.3.4 Compare prokaryotic and eukaryotic cells. prokaryotic is usually smaller in size, Eukaryotic is larger both have cytoplasm prokaryotic has no nucleus, Eukaryotic has a membrane-bound nucleus prokaryotic has one chromosome / circular, Eukaryotic has two or more chromosomes prokaryotic has DNA only, Eukaryotic has DNA with histones to bind together prokaryotic has no membrane-bound organelles, E has some membrane-bound organelles Eukaryotic has mitochondria, prokaryotic does not Eukaryotic has other example of organelle, prokaryotic does not both can have a flagellum if flagella then E has 9+2 fibrils, prokaryotic does not prokaryotic can have pili, E does not prokaryotic can have plasmids, Eukaryotic does not both have ribosomes prokaryotic has small ribosomes, Eukaryotic has larger ones both have cell membrane prokaryotic has cell wall, Eukaryotic has no cell wall Eukaryotic has centriole, prokaryotic has no centriole 2.3.5 State three differences between plant and animal cells. Only plant cells have: Cell walls Chloroplasts Vacuole - more specificially central vacuole Plasmodesmata 2.3.6 Outline two roles of Extracellular components The plant wall maintains shape, prevents excess water uptake, and holds the whole plant up against the force of gravity. Animal cells secrete glycoproteins that form the extracellular matrix (ECM). This functions in support, adhesion and movement. Starch granules for storage of carbohydrates Centrioles Cholesterol in the plasma membrane Glycogen for storage of carbohydrate State the composition and function of the plant cell wall The main component of plant cell walls is cellulose. Cellulose molecules are arranged in bundles called microfibrils. These give the cell wall great tensile strength and allow high pressures to develop inside the cell. extra:The cellulose cell wall consists of three layers: middle lamella, primary cell wall, and secondary cell wall. The overall functions the cell wall preforms are: structure, support, protection.